Authors' objectives

To test, with the best available evidence, the relative efficacy of analgesic interventions that have been used to prevent pain caused by propofol injection.

Searching

MEDLINE (via Datastar and PubMed from 1966 to September 1999), Cochrane Library (1999, issue 3) and EMBASE (from 1982 to February 1999) were searched using different strategies but with the free textwords 'propofol', 'pain', 'injection' and 'random', alone and in combination. The search was not restricted to the English language. Additional trials were identified from reference lists of retrieved reports and from review articles on propofol and pain on injection, and by manually searching locally available anaesthetic journals.

Study selection

Assessment of study quality

Studies were scored for methodological validity using the three-item, five point Oxford scale (see Other Publications of Related Interest no.1). The scale took into account proper randomisation, double-blinding, and reporting of withdrawals and drop-outs. The minimum score of any included RCTs was one, and the maximum score was five. Two authors independently read each report that could possibly meet the inclusion criteria and scored them for methodological quality. A consensus was reached by discussion.

Data extraction

The authors do not state how the data were extracted for the review, or how many of the reviewers performed the data extraction.

Methods of synthesis

Results of the review

Fifty-six studies with a total of 6264 participants were included.

Quality of the included trials.

Most of the trials were of rather a poor quality. Blinding was often inadequate (no further details of study quality such as range of scores was provided).

Effectiveness of the interventions.

On average, 70% of the patients reported pain on injection. Fifteen drugs, 12 physical measurements, and combinations were tested. With IV lidocaine 40 mg, given with a tourniquet 30 to 120 s before the injection of propofol, the number of patients needed to be treated (NNT) to prevent pain in one who would have had pain had they received placebo was 1.6. The closest to this came meperidine 40 mg with tourniquet (NNT 1.9) and metoclopramide 10 mg with tourniquet (NNT 2.2). With lidocaine mixed with propofol, the best NNT was 2.4; with IV alfentanil or fentanyl, it was 3 to 4. IV lidocaine before the injection of propofol was less analgesic. Temperature had no significant effect. There was a lack of data for all other interventions to allow meaningful conclusions. The diameter of venous catheters and speed of injection had no impact on pain.

Authors' conclusions

For best prevention of pain on injection with propofol, lidocaine 0.5 mg/kg should be given with a rubber tourniquet before the propofol injection; of 100 treated patients, approximately 60 have no pain.

CRD commentary

This is a well-written review with clear inclusion and exclusion criteria. The search is reasonable but, with the exclusion of abstracts, the possibility of publication bias cannot be ruled out. The methods of the review are adequately described, but few details of the quality of the included reviews are reported, and the quality of the trials is not taken into account in the analysis. In the analysis, only the numbers need to treat were reported, which are dependent on the prevalence of the condition in the population. It would have been useful to also have a report of the relative risks. Given the above limitations, the author's conclusions should be viewed with caution.

Implications of the review for practice and research

Practice: The authors state that 'IV lidocaine (0.5 mg/kg) should be given with a rubber tourniquet on the forearm, 30 to 120 s before the injection of propofol; lidocaine will prevent pain in approximately 60% of the patients treated in this manner'.

Research: The authors state that, 'The lidocaine-tourniquet method is undeniably effective and simple to perform. This begs the question as to the necessity of clinical studies that may identify yet another intervention with some analgesic efficacy to prevent pain on injection with propofol.

Funding

Swiss National Science Foundation, grant number 3233-051939-97.

Bibliographic details

Picard P, Tramer M R. Prevention of pain on injection with propofol: a quantitative systematic review. Anesthesia and Analgesia 2000; 90(4): 963-969. [PubMed: 10735808]

Original Paper URL

http://www.anesthesia-analgesia.org

Other publications of related interest

1. Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Gavaghan DJ, et al. Assessing the quality of reports of randomized clinical trials: is blinding necessary? Control Clin Trials 1996;17:1-12.

Indexing Status

Subject indexing assigned by NLM

MeSH

Adult; Analgesics, Opioid /therapeutic use; Humans; Injections /adverse effects; Lidocaine /therapeutic use; Pain /prevention & control; Propofol /administration & dosage /adverse effects; Randomized Controlled Trials as Topic; Temperature

AccessionNumber

12000000761

Database entry date

31/08/2001

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.